Many previous systems for supporting shelving, display items, clothes hanger rods and the like have provided for shelf support at discrete heights so that the user cannot select the support height in a continuous fashion. Early efforts to provide for a continuous support system have been unsatisfactory for a number of reasons, including a comparatively high expense of such systems. U.S. Pat. No. 2,703,692, issued Mar. 8, 1955 to Felix discloses a system of uprights and supporting arms intended to permit setting the supporting arm at a required height. The supporting arms of Felix had a side projection which is believed to make it impractical to produce by a stamping operation. More complicated production techniques contribute to the expense of the device. Felix provided for a point on the heel portion of the support for penetrating into the back wall of the upright. Such deformation of the back wall can provide an unsightly device, particularly when a high-finish system is required. The deformation also detracts from infinite adjustability since, whenever the point is positioned sufficiently near a previously formed depression, the pre-existing depression will tend to guide the point of the support away from the desired location, preventing the user from readjusting a shelf to a location close to the original location. Felix provided for a cam action, but considered it necessary to combine this with a wedge device and a point device, and disclosed using the combination of all three to achieve the necessary support.
U.S. Pat. No. 3,865,337 issued Feb. 11, 1975 to Towfigh, et al. discloses a standard and bracket system with a pin secured to the bracket. In the system of Towfigh, a portion of the bracket body is used in maintaining the bracket at the desired height. In particular, a portion of the bracket (the portion between the pin and the back surface) is compressed within the standard. The back surface of the bracket is pressed against the back wall of the standard so that the thickness of the bracket body determines the portion of the back wall over which the clamping pressure is distributed.
Commercial systems employing a pin and bracket system have been found to have relatively high costs, at least partly since a thick bracket body (e.g., 1/4 in. or more) is needed to distribute clamping force over the standard back wall sufficiently to avoid punch-through or rupture of the back wall. This configuration also requires a relatively wide slot to accommodate the wide bracket body. High forces are concentrated on the pin-bracket junction both because of the high clamping forces and the fact that the pin-body junction is a primary component for resisting lateral wobbling of the bracket. The high forces are believed to contribute to enlargement of the pin hole. Attempts to enhance support by employing softer materials such as aluminum (e.g., to provide bearing support as a supplement to friction support) may reduce the bracket lifetime because of the high forces between the pin and the soft metal body. Use of metals such as aluminum for the standard portion of the device result in plastic deformation of the standard leaving gouges or detents in the back wall (which are highly visible because of the wide slot required) and in the front wall (which partially convert the device from a friction clamp to a bearing device). Creation of plastic deformation is enhanced by providing a pin location (with respect to the bracket back surface) which exceeds the standard depth by about 0.02 inches (about 0.5 mm) or more. Formation of gouges or detents limits the continuous nature of the height adjustability since the bracket tends to move to a previously formed detent if an attempt is made to position the bracket near a previous detent.
Accordingly, it would be useful to provide a support system which has continuous height adjustment, is easily manufactured such as by roll forming and/or stamping, and avoids or minimizes gouging or other plastic deformation of components. In one embodiment, previously-available, off-the-shelf steel tubing can be used for the standards.